in early Christian literature—especially in the oldest landmark, the Didache (Teaching of the Twelve Apostles)—the wandering preachers of Christianity.

In the New Testament the term “apostle” is also used as a designation for the closest followers of Christ; synonyms of this meaning are “disciples,” or “the twelve.” According to the Gospels, they were Andrew, Bartholomew, John, Judas Iscariot, Matthew, Peter, Simon Zelotes (or Simon the Canaanite), Thaddeus (or Judas, the son or brother of James), Philip, Thomas, James (son of Alphaeus), and James (son of Zebedee). After Judas Iscariot’s betrayal, Matthias (not to be confused with Matthew) was chosen in his place. Paul also included himself among the apostles. Christian tradition (as expounded in the Acts of the Apostles and in the apocryphal biographies of the apostles) connects the spread of Christianity with the activity of the twelve apostles and Paul. Doubts concerning the historical authenticity of these apostles, expressed by some researchers, are hypercritical. It is certain, however, that neither the so-called Apostles’ Creed nor the apostolic constitutions and canons (which were written later) belong to the apostles.

In contemporary speech apostle is used figuratively to refer to a zealous follower of any kind of idea or doctrine.